Packing machine



July 28, 1942. R. B.`sMlTH ETAL 2,290,916.

PACKING MACHINE Filed May 12. 1939 2 Sheets-Sheet 1 Roscoe a. sMlTH K T WASSEN vEN'roR ATTORNEY :iuly 28, 1942. R. B. sMr'rH ETAL 2,290,915 'PACKING MACHINE Filed May" 12. 1939 2 Sheets-Sheet 2 Fla-2 Roscoe B. SMITH KURT wAssl-:N A

FIG." 3

menen 'Juiyza 1942' PACKING MACHINE nonne n. smith ana'xuri wassen, Wilmington, Del., asignors to Hercules-Powder Company, Wilmington, Del., acorporationof Delaware Application May 12, 1939, serial No. 213.301

6 Claims.

This invention relates to an improved packing machine for tubular containers and more particularly to an improved machine for producingv tubular ycontainers for use in sheathing explosive cartridges.

In the coal miningindustry the use of sheathed explosives is increasing because of the increased '(oi. isz-Vis) amount of lump material such an explosive will produce and because of the name quenching ability of the sheathing. A sheathed explosive usually comprises a cartridge of explosivesur- "rounded by' a sheathing made from a compresvsible materiaLa flame quenching material and in some cases a binder. Ihe entire sheathing acts to absorb some ofthe initial shattering shock produced upon detonation and the fiamequenching material cools or quenches the hot gases and iiame produced. The.- binder is added to aid in forming the sheathing. y

The sheathing used in the explosive industry may be produced from compressible material such as, for example, mica, balsa, bagasse, cork, etc. in admixture with a. ame quenching salt such as,

Having now indicated in a general way the nature and purpose of this invention there follows a more detailed description of preferred embodiments thereof, with `reference to the accompanying drawings in which:

Figure -.1 is a cross section of the assembled packing machine. Figure 2 is an elevation view of the packing worm. Figure 3 is a cross section along line AA of Figure 2. Figure 4 is an elevation view of the feed tube and worm guide, and

.Figure 5 is the top view of the feed tube and worm guide.

The assembly view of the packing machine of this invention as shown in Figure 1 includes a stationary feed tube and worm guide I, also shown by Figures 4 and 5, the packing worm 2,

alsqshown by Figures 2 and 3, a feed hopper l,

for example, sodium bicarbonate, plaster of Paris,

borax, calcium fluoride, etc. and a binding agent such as, for example, sodium silicate, clay, `or glue.

In normal use, the sheathing may include from about 10'to 30% compressible material, about 40' to 90% iiame quenching material, and a small amount of a binder. This type of sheathing is produced by molding, extruding or packing wet ordry materials into the desired tubular form.

There are usually considerable difficulties encountered in forming the sheathing material into a usable form in an efficlent'and economical manner.

commercial handling. Otherobjects will appear hereinafter.

a movable base 4, and a paper tube 5. The general means of operation of the packing machine proceeds as follows: A tub'e 5 of paper, cardboard, plaster, ber, metal,or similar material is slipped on an extension 6 of thejfeed tube and worm guide I, while the base 4, is in the lowered position. The base `4 is then brought into contact with the bottom end and the feed tube ex` the layer 0f packing material until the amount Now in accordance with lthis invention there has been produced a packing machine for preleaving a smooth internal bore and produces a tubularsheath that may be readily handled and easily used to inclose explosive cartridges.

of material packed is suillcient in height to maintain itself in position. This shank 9 makes the packing of a tube sheathing possible by causing .the packing material to form a bore having a smooth interior and bypreventing the packing material, forming the bore, from crumbling ,during. the packing operation. The base 4 containsa hollow III to receive the shank 9 and to'allow the vremoval of any packing material which might drop into the hollow I0 during the removal of the packed sheathing. The feed tubeand worm guide l is equippedwith set screws Il to hold the hopper 3-in position and is; further rigidly mounted in proper relation to the worm 2 and movable base 4. The movable base 4 is so geared orcounterweighted that a predetermined deiinite pressure exerted by the packed material inside the tube 5 forces it downward. It will be To facilitate the detail description 'of the worm, an elevation view is shown in Figure 2 and a cross section of the worm spiral taken along line AA is shown in Figure 3. The worm 2 may be of any desired length, diameter, pitch and spacing depending entirely upon the type and use of sheathingr that is ,tobe packed. For packing 'sheathing to be used with 11A" x 8" dynamite cartridges, we have found` that a worm having an overall diameter of about 119/32" with a worm spiral pitch of about 1" produced very good results. The thickness of the sheathing packed is determined by the diameter of the shank and the inside diameter of the tube used. The shank for 11/4" x 8" cartridges was found to give good results if it was between' l" and 3" long and 15/ 1s" in diameter with the smoothest finished bore and least crumbling produced when the shank was 2" long., There are many means of revolving the worm and such are well known to the art.

The packing operationl is variable depending upon the type sheathing being packed and upon well effects the desired result consists of reducing the width of the spiral within the hopper. It will be understood that each of the above alternative embodiments must be properly coordinated with the various types of packing material to effect thebest operating results.

To increase the speed of packing the width of the Worm spiral may be increased or the shaft between the spiral may be formed in a concave shape. It will be appreciated that the above variable methods can also be adapted to pack sheathing of various thickness. The diameter and \taper of the solid shank must also be coordinated with thev variations made in the packing speed or sheath wall thickness to insure smooth bore products. As illustrated Figure l, shank 9.k is in the form of a truncated cone.

The feed tube and worm guide l as shown in Figures 4 and 5 must, of necessity, be constructed of fairly heavy material around the upper part to allow positive fastening of the hopper by set screws il and also to provide a means of rigidly afxing the guide and feed tube to prevent binding of the worm. The tubular extension, We nd, should preferably be made of thin material to prevent loss of packing emciency.

The packing materials which may be used are varied but compositions containing about one part of compressible material such as mica, balsa, bagas'se, cork, or the like and about 3 to 4 parts of a flame quenching salt such as for example sodium bicarbonate, plaster of Paris, borax, calcium fiuoride or the like, and, if necessary, a minor amount of a binder such as sodium silicate, clay or the like have been found to give excellent results in the machine of this invention. Depending upon the individual physical characteristics of different mixtures, various percentages of water may be used in the mixtures to facilitate packing. i

` I l The capacity of the packing machine in regard 'apparent' that vthe gearing or weighting may be soregulated 'as to give the desired density or hardness of packing.

to the number of cartridges packed is limited by the speed, pitch and taper of the shaft .diameter -of the worm, but we have found that when running a worm having a l-inch pitch at '700 R. P. M., the machine will produce approximately 500 1%." x 8" tubes an hour. The machine as described is designed to produce sheathing for 1%" x 8" cartridges and to run semi-automatic, the machine stopping when the base plate is in the low position at which point the sheath is removed and a new tube placed on the feed tube. The worm starts again when the base plate is raised into contact with the bottom of the feed tube. It will be apparent to those skilled in the art that there are many various means of semiautomatically operating this machine and these various means are to be understood to be within the scope of this invention.

The shank extending from the end of the worm allows a hollow sheathing to be packed without any crumbling of the packing material, but the length of this shank must be so adapted in relation to the diameter of the sheath packed that the pressure of the packing material will not cause crumbling or `collapsing of the packed part of the sheathing whenthe support provided by the shank is removed. The shank which sup- .ports and smooths the sheathing wall may be slightly tapered to allow the packed material to swell slightly as the pressure of the worm is lessened with the lowering of the base `plate Contror of the interior surface of the sheath centers in the design of the shank and for each diameter cartridge the length may vary, but the optimum length is easily determined experimentally.

The machine of this invention is described above is used to pack sheaths for 11A" x 8" dynamite but the machine may also be used to pack sheathing for cartridges varying from about' l/2" to 7" in diameter and from about 4 inches to 24 inches in length. In the production of the short length sheathing long lengths may be packed and cut to length as desired.

It will be understood that the details and examples hereinbefore set forth are illustrative only, and that the invention as herein broadly described and claimed is in no way limitedv said guiding means, a movable base having a central bore, said base capable of contacting the bottom of said guiding means and supporting the said tube, the said shank extending beyond the spiral packing worm a distance at least equal to the diameter of the shank, and said extending lportion 'decreasing in diameter from the shank diameter at the Aend of the spiral to a substantially smaller diameter at the end of said portion whereby the packed sheath is supported without additional compression.

2. A machine for packing tubular sheathingl comprising an annular layer of sheathing material supported -by a substantially rigid tube, which includes a movable base, having a central bore, a tubular guiding means, and a rotatable shank having a spiral screw thereon vextending through said guiding means, 4said shank extendcomprising an annular layer of cushioning material supported by a substantially rigid tube which includes a movable base, having a central bore, a tubular guiding means, and a rotatabieshank having a spiral screw thereon extending through said guiding means, said shank extending a distance at least equal to the diameter of the said shank below the spiral, said extension being tapered from a point adjacent the end of said spiral throughout the length of said extension whereby the end of the extension is of substantially smaller diameter than the shank diameter and the packed sheath is supported without further compression.

4. A machine, for packing tubular sheathing comprising an annular layer of compressible material supported by a substantially rigid tube,

- which includes a tubular guiding means for receiving said tube, a rotatable shank having a spiral packing worm mounted thereon within said guiding means, a vertically movable base having a central bore, said base capable of contating the bottom of said guiding means and supporting the said tube, the said shank extending beyond the spiral packing-worma distance at least equal to the diameter of kthe shank, said extending portion of the shank decreasing in diameter from a point adjacent the end of the spiral to the end of said portion whereby the -packed sheath is supported without additional compression.

5. A machine for packing tubular sheathing comprising an annular layer of sheathing material supported by a substantially rigid tube, which includes a vertically movable base, having a central bore, a stationary tubular guiding means,

and a rotatable shank having a spiral screwthereon extending through said guiding means, said shank extendinga distance at least equal to the diameter of the said shank below the spiral, and said extending portion of the shank being constantly tapered from the shank diameter at the end adjacent the spiral screw to a diameter substantially smaller than the said shank diameter at the-end of said shank, whereby the packed sheath is supported without additional compression.

6. A machine for packing tubular sheathing comprising anannular layer of cushioning material supported by a substantially rig-'id tube which includes a vertically movable base, having a central bore, a stationary tubular guiding means, and a rotatable shank having l a spiral screw thereon extending through said guidingmeans, said shank extending a distance at least equal to the diameter of the said shank below the spiral in the form of atruncated cone. decreasing diameter from a point adjacent the spiral throughout the entire length of said extending portion of the shank whereby the packed sheath is supported without additional compression.

Roscoe B. SMITH. KURT wAssN.

CERTIFICATE oF cQRREcToN. Patent no. 2,290,916. July 28, 19u2.

' RoscoE- B. SMITH, ET AL.

It 1s hereby' certified that error appears inthe printed specificatie ofthe above numberedpatent requiring correction-'as follow-s: Page 2, first 6, elaim 2, for "-wher'ey r-'ead -whereby'; and that the said Letters Patent should be read w 1th,this correct1'on therein that the same may cnfoz'm t'o the record. of the case in the Patent Office.

s1gnec1 end sealed this 1st day of september, ..A. D; 19u2.

. H enry Van Arsdale (Seal) Acting Comnissioner'of Patents. 

